全文获取类型
收费全文 | 9051篇 |
免费 | 552篇 |
国内免费 | 21篇 |
专业分类
电工技术 | 126篇 |
综合类 | 18篇 |
化学工业 | 2339篇 |
金属工艺 | 170篇 |
机械仪表 | 207篇 |
建筑科学 | 321篇 |
矿业工程 | 36篇 |
能源动力 | 223篇 |
轻工业 | 402篇 |
水利工程 | 68篇 |
石油天然气 | 28篇 |
无线电 | 758篇 |
一般工业技术 | 2286篇 |
冶金工业 | 981篇 |
原子能技术 | 78篇 |
自动化技术 | 1583篇 |
出版年
2023年 | 153篇 |
2022年 | 374篇 |
2021年 | 418篇 |
2020年 | 285篇 |
2019年 | 246篇 |
2018年 | 301篇 |
2017年 | 255篇 |
2016年 | 349篇 |
2015年 | 297篇 |
2014年 | 438篇 |
2013年 | 550篇 |
2012年 | 547篇 |
2011年 | 623篇 |
2010年 | 423篇 |
2009年 | 412篇 |
2008年 | 433篇 |
2007年 | 416篇 |
2006年 | 324篇 |
2005年 | 252篇 |
2004年 | 222篇 |
2003年 | 201篇 |
2002年 | 191篇 |
2001年 | 122篇 |
2000年 | 113篇 |
1999年 | 119篇 |
1998年 | 193篇 |
1997年 | 154篇 |
1996年 | 105篇 |
1995年 | 83篇 |
1994年 | 73篇 |
1993年 | 90篇 |
1992年 | 53篇 |
1991年 | 50篇 |
1990年 | 50篇 |
1989年 | 37篇 |
1988年 | 44篇 |
1987年 | 40篇 |
1986年 | 34篇 |
1985年 | 42篇 |
1984年 | 37篇 |
1983年 | 32篇 |
1982年 | 27篇 |
1981年 | 27篇 |
1980年 | 23篇 |
1979年 | 19篇 |
1978年 | 28篇 |
1977年 | 24篇 |
1976年 | 60篇 |
1975年 | 27篇 |
1971年 | 17篇 |
排序方式: 共有9624条查询结果,搜索用时 15 毫秒
21.
22.
23.
IT/Business alignment 总被引:3,自引:2,他引:1
Dr. Alexander Teubner 《WIRTSCHAFTSINFORMATIK》2006,48(5):368-371
24.
Research on sexual abuse frequently fails to address the influence of the family as a risk factor for the onset of all kinds of sexual abuse and as a mediator of its long-term effects. Attachment theory provides a useful conceptual framework for understanding the familial antecedents and long-term consequences of sexual abuse. Themes associated with insecure parent–child attachment (rejection, role reversal/parentification, and fear/unresolved trauma) are frequently found in the dynamics of families characterized by sexual abuse, and specific categories of sequelae are related to probable attachment experiences. Implications for intervention and research on sexual abuse are suggested. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
25.
Castonguay Louis G.; Schut Alexander J.; Aikens Deane E.; Constantino Michael J.; Laurenceau Jean-Philippe; Bologh Laura; Burns David D. 《Canadian Metallurgical Quarterly》2004,14(1):4
This study is a preliminary investigation of an integrative treatment aimed at improving the efficacy of cognitive therapy (CT) for depression. The development of the treatment protocol was based on process findings, which suggested that strategies used in CT to resolve alliance ruptures may actually exacerbate problems in the therapeutic relationship. The protocol integrates, within the traditional CT treatment manual, procedures to repair alliance ruptures that are derived from or consistent with humanistic and interpersonal therapies. Although conducted by inexperienced therapists, the integrative treatment led to greater improvement than a waiting-list condition. The results also compare favorably to previous findings for CT. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
26.
Alexander Weinmann 《e & i Elektrotechnik und Informationstechnik》2008,125(1-2):1-1
Ohne Zusammenfassung 相似文献
27.
Paustovskii Alexander V. Alfintseva Raisa A. Kurinnaya Tatyana V. Pogorelaya Valentina V. Kirilenko Stepan N. 《Powder Metallurgy and Metal Ceramics》2004,43(5-6):251-257
The main parameters of electrospark alloying of steel 45 with anodes made from Ni – Cr – Al – Y alloys have been investigated. The anodes were fabricated by casting and hot pressing. The highest values of the mass transfer coefficient were observed in the case of electrospark alloying with hot-pressed alloys. Microstructure and x-ray phase analyses of electrospark coatings revealed the presence of solid solutions based on nickel, iron, chromium as well as intermetallic compounds. Coatings obtained by electrospark alloying with hot-pressed alloy are more wear-resistant than are coatings obtained by alloying with cast alloys. 相似文献
28.
Alexander Babich Konstantinos Mavrommatis Dieter Senk Heinrich Wilhelm Gudenau 《国际钢铁研究》2004,75(7):428-432
This contribution deals with advanced educational technologies needed to equip customers from higher education institutions, research and industry with efficient tools supporting their work and operating new skills‐training methods. The challenges are reducing the training costs, improving quality and increasing the number of graduates in engineering departments. The concept of a Virtual Lab based on the combination of various teaching methods and tools is presented. Principles of mathematisation in metallurgical education and training are discussed. An example of online course designed in the form of Virtual Lab is demonstrated. 相似文献
29.
A new high-order accurate continuous Galerkin method for linear elastodynamics problems 总被引:1,自引:1,他引:0
Alexander V. Idesman 《Computational Mechanics》2007,40(2):261-279
A new high-order accurate time-continuous Galerkin (TCG) method for elastodynamics is suggested. The accuracy of the new implicit
TCG method is increased by a factor of two in comparison to that of the standard TCG method and is one order higher than the
accuracy of the standard time-discontinuous Galerkin (TDG) method at the same number of degrees of freedom. The new method
is unconditionally stable and has controllable numerical dissipation at high frequencies. An iterative predictor/multi-corrector
solver that includes the factorization of the effective mass matrix of the same dimension as that of the mass matrix for the
second-order methods is developed for the new TCG method. A new strategy combining numerical methods with small and large
numerical dissipation is developed for elastodynamics. Simple numerical tests show a significant reduction in the computation
time (by 5–25 times) for the new TCG method in comparison to that for second-order methods, and the suppression of spurious
high-frequency oscillations. 相似文献
30.
S.B. Burson D. Bradley J. Brockmann E. Copus D. Powers G. Greene C. Alexander 《Nuclear Engineering and Design》1989,115(2-3)
The NRC's Research Program on Core-Debris/Cavity Interactions comprises two principal elements: (1) an analytical effort focused primarily on development of computer codes needed to predict the potential consequences of risk-significant severe-accident scenarios; and (2) an experimental component to provide insights into the relevant phenomenological processes and to develop the experimental data base necessary for validation of the codes. The analytical activities at Sandia National Laboratories (SNL) focus primarily on refinement and validation of the CORCON and VANESA codes. Two major experimental activities are also based at SNL: (1) the large-scale SURC tests address the thermal-hydraulic phenomena in the cavity as well as aerosol release associated with prototypical core-melt materials in various types of concrete crucibles, while (2) the WITCH and GHOST experiments are concerned with aerosol generation and radionuclide release phenomena. A program of small-scale special-effects tests at Brookhaven National Laboratory (BNL) is coupled to a concomitant model-development and code-validation activity. In addition, measurements are being made at Battelle Columbus Laboratory (BCL) to augment the thermochemical data base needed in the VANESA code to permit refined radiological source-term predictions. The current scope and status of this research is reviewed. 相似文献